This mechanical card features a couple dancing the Tango. Fun ballroom dance theme! It is mechanical -- the woman's leg moves. I would date this as 1930's, and it is fabulous!
An adorable little girl with dark hair in ringlets - probably 1930's vintage:
Sweet homemade card for teacher dated 1939 -- look at the tiny little envelope child has made on the front of the card:
1942 card with children riding an old fashioned teeter totter playground toy:
1942 card for teacher -- especially beautiful illustration showing children around the globe:
Again, all these cards - and more! - are at Birdhouse Books!